Water and Carbon Cycles

What Water and Carbon Cycles covers

Water and Carbon Cycles is examined in Component 2, Global Systems and Global Governance. It covers systems, mass balance and the water balance, global water stores, their size and residence times, changing stores: sea level change and cryospheric processes, the drainage basin as an open system, precipitation inputs and interception, infiltration, overland flow and throughflow, percolation, groundwater flow, channel flow and basin outputs, river regimes and the factors that control them, the storm hydrograph: components and shape, climatic factors influencing storm hydrographs, catchment factors influencing storm hydrographs, cloud formation and theories of precipitation, excess runoff: natural and human causes, deficit in the water cycle and aquifer recharge, the global carbon cycle: stores, fluxes and mass balance, fast carbon pathways between land and atmosphere, ocean and atmosphere exchange and the slow carbon cycle, carbon stores in tropical rainforest and temperate grassland, land-use change and the carbon store, peatlands and the changing carbon store, rising atmospheric carbon, the energy budget and its impacts and feedback, thresholds and permafrost thaw.

The 22 subtopics

Each one has its own page.

• Systems, mass balance and the water balanceFour components of any system, open and a closed system and store within the water cycle.Open →
• Global water stores, their size and residence timesWhere the planet's water actually sits — oceans, ice, groundwater, soil, atmosphere — with the share held in each and how long a molecule stays there, from days in the air to millennia in an ice sheet.Open →
• Changing stores: sea level change and cryospheric processesComponents of the cryosphere, accumulation as it applies to a glacier and glacier's mass balance.Open →
• The drainage basin as an open systemDrainage basin, interception store and surface store.Open →
• Precipitation inputs and interceptionFive types of precipitation, precipitation amount, duration and intensity and interception loss.Open →
• Infiltration, overland flow and throughflowInfiltration capacity and overland flow.Open →
• Percolation, groundwater flow, channel flow and basin outputsGroundwater flow, channel flow and unit of river discharge.Open →
• River regimes and the factors that control themRiver regime, river with a snowmelt-dominated regime and monsoon regime.Open →
• The storm hydrograph: components and shapePeak discharge, lag time and rising limb of a hydrograph.Open →
• Climatic factors influencing storm hydrographsAntecedent conditions and why convectional storms produce flashier hydrographs than frontal rain.Open →
• Catchment factors influencing storm hydrographsDrainage density, porosity and permeability and rock that is porous but not very permeable.Open →
• Cloud formation and theories of precipitationAdiabatic cooling, dry adiabatic lapse rate and dew point.Open →
• Excess runoff: natural and human causesExcess runoff, how embankments and levees can make flooding worse and river basin mismanagement.Open →
• Deficit in the water cycle and aquifer rechargeWater deficit, meteorological and hydrological drought and agricultural drought.Open →
• The global carbon cycle: stores, fluxes and mass balanceFive major stores of carbon on Earth, carbon flux and carbon sink and a carbon source.Open →
• Fast carbon pathways between land and atmosphereNet primary productivity, decomposition as a carbon pathway and carbon sequestration.Open →
• Ocean and atmosphere exchange and the slow carbon cyclePhysical or solubility pump, biological pump and carbonate pump.Open →
• Carbon stores in tropical rainforest and temperate grasslandTypical net primary productivity for tropical rainforest and typical net primary productivity for temperate grassland.Open →
• Land-use change and the carbon storeLand-use change in the context of the carbon cycle, one limitation of afforestation as a carbon strategy and conservation agriculture.Open →
• Peatlands and the changing carbon storeHow peat forms, two ways in which peat has been extracted and two techniques used to restore a damaged peatland.Open →
• Rising atmospheric carbon, the energy budget and its impactsGreenhouse effect in terms of the energy budget, radiative forcing and ocean acidification.Open →
• Feedback, thresholds and permafrost thawPositive feedback, negative feedback and threshold in a natural system.Open →

What you need to know

Answer each one before you reveal it.

Take Water and Carbon Cycles further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Infiltration vs Percolation

  Infiltration: water passing from the surface into the soil. Percolation: water passing from the soil into the bedrock.

• Porosity vs Permeability

  Porosity: how much pore space a rock or soil has. Permeability: how easily water passes through it.

• Discharge vs Velocity

  Discharge: the volume of water passing through a cross-section each second. Velocity: the speed of the water alone.

Questions from this topic

Each one with the model answer underneath.

1. 1

   What are the four components of any system?

   Model answer

   Every system has inputs, outputs, stores and flows. Inputs add matter or energy, outputs remove it, stores hold it and flows move it between stores.

2. 2

   Distinguish between an open and a closed system.

   Model answer

   An open system exchanges both matter and energy with its surroundings. A closed system exchanges energy but not matter across its boundary.

3. 3

   Is the global hydrological cycle open or closed, and why?

   Model answer

   The global hydrological cycle is closed for water because no water enters or leaves the planet in significant amounts. Energy from the Sun crosses the boundary freely, so the cycle is open to energy.

4. 4

   Why is a drainage basin described as an open system?

   Model answer

   A drainage basin gains water as precipitation from outside its boundary and loses it as discharge and evapotranspiration. Water therefore crosses the watershed in both directions.

5. 5

   Define a store within the water cycle.

   Model answer

   A store is a reservoir where water is held for a period of time before moving on. Oceans, ice sheets, groundwater and the atmosphere are all stores.

6. 6

   Define a flux in the water cycle.

   Model answer

   A flux is the rate at which water moves from one store to another. Evaporation, precipitation and river discharge are all measured as fluxes.

What is inside Levo

Six ways to work the same material.

Water and Carbon Cycles revision questions

What does Water and Carbon Cycles cover in Eduqas A-Level Geography?

22 subtopics: systems, mass balance and the water balance, global water stores, their size and residence times, changing stores: sea level change and cryospheric processes, the drainage basin as an open system, precipitation inputs and interception, infiltration, overland flow and throughflow, percolation, groundwater flow, channel flow and basin outputs, river regimes and the factors that control them, the storm hydrograph: components and shape, climatic factors influencing storm hydrographs, catchment factors influencing storm hydrographs, cloud formation and theories of precipitation, excess runoff: natural and human causes, deficit in the water cycle and aquifer recharge, the global carbon cycle: stores, fluxes and mass balance, fast carbon pathways between land and atmosphere, ocean and atmosphere exchange and the slow carbon cycle, carbon stores in tropical rainforest and temperate grassland, land-use change and the carbon store, peatlands and the changing carbon store, rising atmospheric carbon, the energy budget and its impacts and feedback, thresholds and permafrost thaw. Each one has its own page with questions and model answers.

How is Water and Carbon Cycles organised?

By the Eduqas A110QS specification, subtopic by subtopic, so it matches the order you are taught it in.